A program for analyzing transient and steady-state soil gas pump tests

Journal Article · Mon Jul 01 04:00:00 EDT 1996 · Ground Water

DOI:https://doi.org/10.1111/j.1745-6584.1996.tb02064.x· OSTI ID:260489

Falta, R W ^[1]

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1. Clemson Univ., SC (United States)

Soil vapor extraction (SVE) is a widely used method for removing volatile organic compounds (VOCs) from the unsaturated zone. With this technique, a vacuum is applied to wells screened above the water table. This induces soil gas flow towards the wells, resulting in the evaporation of nonaqueous phase liquids (NAPLs), and the removal of VOC vapors from the unsaturated zone. The field determination of unsaturated zone properties controlling the gas flow is an important part of the SVE system design process. Soil gas pump tests are commonly performed to identify important unsaturated zone parameters such as the effective gas permeability tensor and the influence of tight or leaky confining units. An interactive FORTRAN computer program called GASSOLVE has been developed for analyzing these tests under both transient and steady-state conditions. The code uses one of two general analytical solutions for radially symmetric gas flow to a well: the solution for transient compressible gas flow to a partially penetrating well in which the ground surface is open to the atmosphere; and the solution of transient compressible gas flow to a partially penetrating well bounded above by a leaky confining layer. Pump tests involving steady-state conditions, fully penetrating wells, or tight confining layers are considered as special cases of these solutions. The field gas pressure data from multiple observation wells are inverted using a multidimensional nonlinear optimization routine to provide a best fit of the data with the selected analytical solution.

• Sponsoring Organization: USDOE
• OSTI ID: 260489
• Journal Information: Ground Water, Journal Name: Ground Water Journal Issue: 4 Vol. 34; ISSN GRWAAP; ISSN 0017-467X
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
G CODES
GAS ANALYSIS
ORGANIC COMPOUNDS
REMEDIAL ACTION
REMOVAL
SOILS
STEADY-STATE CONDITIONS
VOLATILE MATTER